scholarly journals ON THE SHEAR STRESS AT THE INTERFACE AND ITS EFFECTS IN THE STRATIFIED FLOW

1964 ◽  
Vol 1 (9) ◽  
pp. 51
Author(s):  
Toshio Iwasaki
Keyword(s):  
Shear Stress ◽  
Internal Waves ◽  
Empirical Equation ◽  
Pure Water ◽  
Stratified Flow ◽  
Experimental Results ◽  
Theoretical Considerations

At the moderate velocity of the pure water which lies on the quiet sal£ water stable internal waves appear at the interfac in the stratified flow, and these waves will break and violated surface will arise if the velocity of the pure water may be increased. In this phase of phenomena the shear stress at the interface has the most important part. However observed aalues of this shear stress have not been reported in the systematic style. Experiments have been conducted in our laboratory since i960. Some theoretical considerations could be served to get an empirical equation on the mterfacial shear using experimental results and data presented by other researchers.

The viscosity of dilute aqueous nonelectrolyte solutions

1981 ◽  
Vol 34 (11) ◽  
pp. 2283 ◽  
Author(s):  
DM Alexander ◽  
DC Moy
Keyword(s):  
Aqueous Solutions ◽  
Temperature Dependence ◽  
Empirical Equation ◽  
Pure Water ◽  
Entropy Change ◽  
Aqueous System ◽  
Experimental Results ◽  
Dilute Solutions ◽  
Molar Entropy ◽  
B Coefficients

An equation is proposed to describe the viscosity B coefficients for dilute solutions of nonelectrolytes in water. It is based on an empirical equation developed for nonaqueous mixtures and an assumption that the entropy change on solution of the liquid solute affects the viscosity of the aqueous system in the same way as a change of molar entropy affects the viscosity of pure water. The equation is shown to represent experimental results well and is especially successful in representing the temperature dependence of the B coefficient for aqueous solutions of alcohols.

Experimental Study on the Specific Heat Capacity Measurement of Water-Based Al2O3-Cu Hybrid Nanofluid by using Differential Thermal Analysis Method

2019 ◽  
Vol 15 ◽  
Author(s):  
Andaç Batur Çolak ◽  
Oğuzhan Yıldız ◽  
Mustafa Bayrak ◽  
Ali Celen ◽  
Ahmet Selim Dalkılıç ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Thermophysical Properties ◽  
Volume Concentration ◽  
Pure Water ◽  
Heat Capacity Measurement ◽  
Experimental Results ◽  
Hybrid Nanofluid ◽  
Capacity Measurement

Background: Researchers working in the field of nanofluid have done many studies on the thermophysical properties of nanofluids. Among these studies, the number of studies on specific heat are rather limited. In the study of the heat transfer performance of nanofluids, it is necessary to increase the number of specific heat studies, whose subject is one of the important thermophysical properties. Objective: The authors aimed to measure the specific heat values of Al2O3/water, Cu/water nanofluids and Al2O3-Cu/water hybrid nanofluids using the DTA method, and compare the results with those frequently used in the literature. In addition, this study focuses on the effect of temperature and volume concentration on specific heat. Method: The two-step method was used in the preparation of nanofluids. The pure water selected as the base fluid was mixed with the Al2O3 and Cu nanoparticles and Arabic Gum as the surfactant, firstly mixed in the magnetic stirrer for half an hour. It was then homogenized for 6 hours in the ultrasonic homogenizer. Results: After the experiments, the specific heat of nanofluids and hybrid nanofluid were compared and the temperature and volume concentration of specific heat were investigated. Then, the experimental results obtained for all three fluids were compared with the two frequently used correlations in the literature. Conclusion: Specific heat capacity increased with increasing temperature, and decreased with increasing volume concentration for three tested nanofluids. Cu/water has the lowest specific heat capacity among all tested fluids. Experimental specific heat capacity measurement results are compared by using the models developed by Pak and Cho and Xuan and Roetzel. According to experimental results, these correlations can predict experimental results within the range of ±1%.

Investigation on the Rheological Behavior of Polyamide6/Montmorillonite Nanocomposites by Reactive Extrusion

2011 ◽  
Vol 233-235 ◽  
pp. 1998-2001 ◽  
Author(s):  
Ming Zhao ◽  
Xiao Zhong Lu ◽  
Kai Gu ◽  
Xiao Min Sun ◽  
Chang Qing Ji
Keyword(s):  
Activation Energy ◽  
Shear Stress ◽  
Shear Rate ◽  
Rheological Behavior ◽  
Reactive Extrusion ◽  
Shear Thinning ◽  
Experimental Results ◽  
Montmorillonite Nanocomposites

The rheological behavior of PA6/montmorillonite(MMT) by reactive extrusion was investigated using cone-and-plate rheometer. The experimental results indicated that PA6/MMT exhibited shear-thinning behavior. The shear stress of both neat PA6 and PA6/MMT increased with the increase in the shear rate. The reduction of the viscous activation energy with the increase of shear stress reflected PA6/MMT can be processed over a wider temperature.

Failure Analysis of Laminates Single-Lap Adhesive Joints under Uniaxial Tensile Loading

2012 ◽  
Vol 490-495 ◽  
pp. 2201-2204
Author(s):  
Yin Huan Yang
Keyword(s):  
Shear Stress ◽  
Tensile Loading ◽  
Adhesive Joints ◽  
Experimental Results ◽  
Uniaxial Tensile ◽  
Tension Tests ◽  
Different Types ◽  
Uniaxial Tensile Loading ◽  
Overlap Area ◽  
Main Factor

Tension tests on three different types of T700/EXOPY unidirectional laminates single-lap adhesive joints under uniaxial tensile loading were performed and effect of adherend thickness and spew fillets on strength of single-lap adhesive joints were analyzed in this paper. According to the experimental results, it is found that joint strength was not linear with the adherend thickness and much affected by spew fillets in overlap ends. At the same time, finite element simulations are carried out to analyze the peel/shear stress fields along joint interfaces and the intermediate layer of adhesive. The simulation results show that it is the main factor to leading to joint failure that the maximum peel/shear stress is occurred at overlap area edges and peel/shear stress of joints with spew fillet at the overlap area edges is less than that of joints with no spew fillet. Good agreements between the present simulations and the experimental results are found.

Modeling Hydroplaning and Effects of Pavement Microtexture

2005 ◽  
Vol 1905 (1) ◽  
pp. 166-176 ◽  
Author(s):  
G. P. Ong ◽  
T. F. Fwa ◽  
J. Guo
Keyword(s):  
Three Dimensional ◽  
Flow Simulation ◽  
Experimental Results ◽  
Tire Pressure ◽  
Finite Volume Model ◽  
Proposed Model ◽  
Loss Of Contact ◽  
The One ◽  
Theoretical Considerations ◽  
Good Agreement

Hydroplaning on wet pavement occurs when a vehicle reaches a critical speed and causes a loss of contact between its tires and the pavement surface. This paper presents the development of a three-dimensional finite volume model that simulates the hydroplaning phenomenon. The theoretical considerations of the flow simulation model are described. The simulation results are in good agreement with the experimental results in the literature and with those obtained by the well-known hydroplaning equation of the National Aeronautics and Space Administration (NASA). The tire pressure–hydroplaning speed relationship predicted by the model is found to match well the one obtained with the NASA hydroplaning equation. Analyses of the results of the present study indicate that pavement microtexture in the 0.2- to 0.5-mm range can delay hydroplaning (i.e., raise the speed at which hydroplaning occurs). The paper also shows that the NASA hydroplaning equation provides a conservative estimate of the hydroplaning speed. The analyses in the present study indicate that when the microtexture of the pavement is considered, the hydroplaning speed predicted by the proposed model deviates from the speed predicted by the smooth surface relationship represented by the NASA hydroplaning equation. The discrepancies in hydroplaning speed are about 1% for a 0.1-mm microtexture depth and 22% for a 0.5-mm microtexture depth. The validity of the proposed model was verified by a check of the computed friction coefficient against the experimental results reported in the literature for pavement surfaces with known microtexture depths.

The Strength of Thick-Walled Cylinders

1959 ◽  
Vol 81 (2) ◽  
pp. 95-111 ◽  
Author(s):  
B. Crossland ◽  
S. M. Jorgensen ◽  
J. A. Bones
Keyword(s):  
Shear Stress ◽  
Mild Steel ◽  
Close Agreement ◽  
Large Strain ◽  
Tension Test ◽  
Experimental Results ◽  
Maximum Pressure ◽  
Strain Behavior ◽  
Pressure Tests ◽  
Strain Data

Comprehensive pressure tests have been carried out on thick-walled, closed-ended cylinders made from a mild steel and a hardened and tempered steel, the maximum pressure reached being 94,000 lb/in.2 The complete theoretical behavior of the cylinders is computed from shear stress-strain data obtained from torsion tests and is shown to be in very close agreement with the experimental results. In addition, a method is given for deriving the large strain behavior of the cylinders from tension test data. When compared with the experimental results this approach gives larger errors, the theoretical values of pressure being consistently high. Finally, ultimate pressures have been calculated from two empirical expressions.

scholarly journals The distortion of crystals of aluminium under compression. Part III.―Measurements of stress

1927 ◽  
Vol 116 (773) ◽  
pp. 39-60 ◽  
Keyword(s):  
Shear Stress ◽  
Large Range ◽  
Experimental Results ◽  
The Other ◽  
Shear Stresses ◽  
Measurable Difference ◽  
The Relationship ◽  
Do So

Several experiments were devised to find out whether it is possible to measure the internal shearing stresses in a compressed disc, and the conditions under which it is possible to do so. Equations are developed for analysing shear stresses parallel to planes of slip and distortion due to double and single slipping. The relationship between shear stress and amount of shear is found for tensile and for compression specimens, when slipping is confined to one plane. The experimental results in the two cases are identical. The fact that the component of force normal to plane of slip is a pressure in one case and a tension in the other makes no measurable difference to resistance to slipping for given amount of slip. During double slipping resistance to shear increases more rapidly for a given total amount of slipping than when all slip is confined to one plane. The experiments cover a large range and show that resistance to shear goes on increasing up to greatest amounts of distortion used.

Experimental Investigation of Oscillating Heat Pipe With Hybrid Fluids of Liquid Metal and Water

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Tingting Hao ◽  
Hongbin Ma ◽  
Xuehu Ma
Keyword(s):  
Heat Transfer ◽  
Liquid Metal ◽  
Heat Pipe ◽  
Heat Input ◽  
Heat Transfer Performance ◽  
Pure Water ◽  
Experimental Results ◽  
Working Fluid ◽  
Transfer Performance ◽  
Oscillating Heat Pipe

A new oscillating heat pipe (OHP) charged with hybrid fluids can improve thermal performance. The key difference in this OHP is that it uses room temperature liquid metal (Galinstan consisting of gallium, indium, and tin) and water as the working fluid. The OHP was fabricated on a copper plate with six turns and a 3 × 3 mm2 cross section. The OHP with hybrid fluids as the working fluid was investigated through visual observation and thermal measurement. Liquid metal was successfully driven to flow through the OHP by the pressure difference between the evaporator and the condenser without external force. Experimental results show that while added liquid metal can increase the heat transport capability, liquid metal oscillation amplitude decreases as the filling ratio of liquid metal increases. Visualization of experimental results show that liquid metal oscillation position and velocity increase as the heat input increases. Oscillating motion of liquid metal in the OHP significantly increases the heat transfer performance at high heat input. The lowest thermal resistance of 0.076 °C/W was achieved in the hybrid fluids-filled OHP with a heat input of 420 W. We experimentally demonstrated a 13% higher heat transfer performance using liquid metal as the working fluid compared to an OHP charged with pure water.

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